An autonomous vehicle is a motorized vehicle that can operate without a human driver. Unlike human-operated vehicles where a passenger could ask a driver about the vehicle's condition, the current travel route, or other similar matters, a passenger of an autonomous vehicle frequently directs such inquires to a customer support agent stationed at a remote location. A user interface device is incorporated in the autonomous vehicle to connect the passenger to customer support, which may include interacting with a live support agent. While the user interface device can be configured to provide support through both visual and audio/verbal interaction, hearing-impaired passengers are typically limited to visual communications, such as written messages.
Problematically for autonomous vehicles is that communication systems oftentimes transmit communications through wireless Internet Protocol (IP) services that can be limited technologically with respect to transmission of Text Telephone (TTY) communications conventionally used by hearing-impaired individuals. For example, TTY communications such as Baudot character strings defined by 1400 to 1800 Hz tones can generate an echo or continuous noise when transmitted over IP networks, despite echo cancellation techniques intended to improve the quality of IP-based communications. TTY communications are also more prone to packet loss than conventional voice services, wherein packets of data transmitted over the IP network do not reach the intended recipient.
Although some compression coders/decoders (codecs) such as G.711 and quality-of-service techniques can allow Voice over Internet Protocol (VoW) networks to support TTY communications, they are bandwidth intensive and therefore not favorable for bandwidth efficient wireless networks of autonomous vehicles. Further, some bandwidth management algorithms apply compression techniques that, while optimized for voice communications, can distort TTY tones. Consequently, when either a Baudot start bit or Baudot stop bit is impaired, synchronization is lost between sending and receiving TTY devices, rendering the transmission unintelligible unless/until synchronization is reestablished.
Thus, implementation of TTY over VoIP may not be a desirable solution in the autonomous vehicle context to satisfy the needs of the hearing-impaired community. In addition, alternative communication techniques defined by messaging environments that transmit and receive text communications (e.g., long-term evolution (LTE) networks) commonly require individuals to type out an entire message before sending the message to a recipient. The recipient of the message can then respond with their own communication by typing an entire reply message before sending the reply message back to the individual. As a result, the nature of generating communications on a message-by-message basis creates a delay that can be undesirable while the sender is typing their message.